In the handling of fluids, and particularly of liquids, such as solutions of various types, which may be adapted for or used in a variety of chemical, industrial, medical, or other processes or techniques, where contaminants or impurities may be encountered, or may accumulate, in the liquid or the solution, it has been customary to filter out such contaminants and impurities, by chemical means or mechanical means, or both. Known filtering equipment generally adapted to what may be called mechanical interception of particles, has included a chamber, or a conduit, through which the liquid to be filtered is passed, and it has been known to enclose in such chamber or conduit a filter body or cartridge, of a more or less porous nature, adapted to pick up and retain the undesirable particles, and such cartidges have been so housed in the chamber or conduit that the liquid to be filtered must pass through the cartridge.
When such a cartridge has accumulated the undesirable particles to such a degree that the cartridge is no longer capable of further efficient or adequate filtering action, the cartridge is removed from the equipment, cleand, and replaced; or it can be removed and discarded, and a new cartridge applied. For such filtering equipment, a typical cartridge may comprise an elongated cylinder, formed generally of fibrous material, and of a rather thick body wall, with an axial bore or hollow; and it has been known to pass the liquid to be purified, into such bore ad thence through the wall of the cylinder, to an outlet space; or, more usually, to apply the liquid to the outside cylindrical wall of the cartridge, and have it pass through the wall, and then pass out of one or both ends of the bore.
It is also known to make such cartridges in large part of yarns, threads, or textiles laid up on a perforated or foraminous core or tube, the center of which constitutes the axial bore of the cartridge.
It is found in practice that cartridges supplied from different sources may vary, considerably, in their dimensions, and especially in their length, from a specified figure; either due to the materials from which they are made, the mode of winding or laying them up, shrinkages which sometimes occur, or perhaps other causes; and this has presented problems in mounting, sealing, and replacing cartridges, relative to the fixed environmental structure of the known types of filtering equipment.
Such problems present difficulties, not only with relation to the need for fluid-tightness so as to prevent bypassing of the filter cartridge by all or part of the liquid to be filtered; but also because, in some instances, ill-fitting, or improperly seated and sealed cartridges, make it difficult to properly enclose them in the environmental structure so that there is a risk of losing valuable liquids, and a risk of danger to the environmental structure, either physically, or chemically (when the liquid being filtered is of a corrosive or other dangerous character; and in some cases there has been a danger from poisonous liquids and/or dangerous fumes, where the filtering equipment is subject to leakage.
In the foregoing, and in what follows, the terms fluids, liquids, and solutions, may be used interchangeably, excepting where the prior art imposes limitations with respect thereto or where the context otherwise indicates or requires.